Folding device using the photo glow tubes



p 9 I R. s. ELBERTY, JR I 2,015,550

FOLDING DEVICE USING THE PHOTO GLOW TUBES Filed Feb. 28) 1951 WITNESSES I lNVENTOR Raberz Sillberfy. Jr.

' AT'TORNEY Patented Sept. 24, 1935 PATENT OFFICE FOLDING DEVICE USING THE PHOTO GLOW TUBES Robert S. Elberty, Jr., Wilkinsburg, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application February 28, 1931, Serial No. 519,097

11 Claims.

My invention relates to sheet-folding apparatus and has particular relation to apparatus for folding flatwork, particularly usable in a launy.

Heretofore, so far as I am aware, flatwork has been folded in a laundry by hand. This process has taken considerable time and has entailed considerable expense.

On the other hand, an automatic device for accomplishing this purpose has been considered almost an impossibility, in view of the fact that it is highly undesirable to make contact between the fiatwork, which-has recently been laundered, and rollers or other appliances that are necessary in operating circuits of electromagnetic folding machines.

It is, accordingly, an object of my invention to provide apparatus for folding laundered flatwork.

Another object of my invention is to provide a. device for folding sheets that may be operated without any contact being made with the sheets.

An ancillary object of my invention is to provide a sheet-folding device that shall fold the sheets with accuracy.

-A further ancillary object of my invention is to provide sheet-folding apparatus whereby sheets of different lengths shall be automatically folded at predetermined positions proportional to their lengths.

More concisely stated, it is an object of my invention to provide a system of conveyors for laundered flatwork, or for sheets of a similar type, that shall not only advance the sheets from one position to another but shall also fold the sheets as they are advanced.

According to my invention, I provide a plurality of pairs of conveyors, one conveyor of each pair (hereinafter designated as a transmitting conveyor) being adapted to advance the sheets that are to be folded, and the remaining conveyor (hereinafter designated as a folding conveyor) being adapted to coact with the former conveyor to fold the sheets and to advance them to another conveyor or to a container wherein the folded sheets are deposited.

The folding operation is initiated by the action of the light, reflected from a sheet, upon a. photosensitive device that is so connected to the motor driving the folding conveyor that the direction of motion of the latter is reversed when the photo-sensitive device comes under the influence cf thesheet. Since, under ordinary circumstances, it is desirable that each sheet be folded in the center, the second conveyor is provided with a rack that coacts with a pin rigidly connected to the photo-sensitive device and advances the photo-sensitive device in the direction in which the folding conveyor is moving when it is reversed. The photo-sensitive device thus moves 5 in a direction opposite to the direction of motion of the unfolded sheet, and, consequently, passes out of the influence thereof when only one-half of the sheet has passed from the transmitting conveyor to the folding conveyor.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, as regards its organization and its operation, together with additional objects and 15 advantages thereof, will best be understood from the following description of a specific embodiment, when read in connection with the accompanying drawing in which,

Figure 1 is a view, in side elevation, showing 20 the principal elements of a system of conveyors constructed according to my invention,

Fig. 2 is a view, in side elevation, showing, in detail, the driving apparatus for the photo-sensitive device that regulates the direction of mo- 25 tion of the folding conveyor, and

Fig. 3 is a diagrammatic view showing a circuit that may be utilized in connection with a photo-sensitive device to reverse the direction of motion of the folding conveyor.

The apparatus shown in the drawing comprises a transmitting conveyor adapted to advance the unfolded sheets 3 of flatwork, and a folding conveyor 5 adapted to receive the'sheets 3 from the first conveyor I and to advance them to a container or to another system of. conveyors that are adapted to fold the sheets again. The latter elements are not shown in the drawing.

The conveyor belts I and 5 are constructed of any suitable material and their surfaces are or- 40 dinarily rendered non-reflective. I have found that black belts of suitable dimensions are entirely satisfactory in the present embodiment of my invention. Each of the belt conveyors I and 5 passes over a plurality of pulleys l, 9, II and i3, the pulley i being driven from a prime mover (not shown) and the pulley 13 being driven from a motor l5 that is adapted to be reversed.

A photosensitive means, comprising a lamp l1 and a photo-tube I9, is mounted in a container 2| in such manner thatthe light from the lamp ll, reflected from the sheet 3 disposed on a surface of the conveyor, is adapted to impinge on the cathode 23 of photo-tube l9. The lamp l1 and the photo-tube l9 are mounted in independent and light-tight chambers and 21 of the container 2|. The container 2| is supported on' a bracket 29 that is equipped with a plurality of pins 3| and 33 that engage cam slots 35 and 31 milled in a plate 39 that is mounted adjacent to the conveyors I and 5.

The bracket 29, supporting the container 2|, is equipped with a finger 4| to engage the teeth 43 of. a rack 45 that is rigidly fixed to the folding conveyor belt 5 and is movable therewith. The teeth 43 of the rack 45 are of such structure that they engage the finger when the upper run 41 of the folding conveyor belt 5 is moving in a direction opposite to the direction of motion of the upper half 49 of the transmitting conveyor belt- I.

However, when the corresponding sections 41 and 49 are moving in the same direction, the finger 4| engages the teeth 43 only during a predetermined portion of its movement. When the finger 4| has been advanced to such point that the light beam impinges upon the end of the transmitting conveyor it is raised by the coaction of a pin 5|, projecting from the surface of the plate 39 supporting the bracket 29 of the photo-sensitive system, and a cam 53, projecting from the finger 4| and rigidly fastened thereto. The cam slots 35 and 31 in the plate 39 supporting the bracket 29 are of such geometric dimensions as to correspond to the motion of the finger 4|.

When the finger 4| is raised to such height that it is not engaged by.the teeth 43 of the rack 45, advancing in the same direction as the upper portion 49 of the transmitting belt I, the photo-sensitive device 2| is at rest, relative to the transmitting belt. However, when a sheet 3, passing under the beam of light, causes the photo-sensitive device to become excited, the direction of motion of the folding conveyor 5 is reversed, and the teeth 43 of the rack 45, which are of bevelled structure,

and, consequently, of greater height on one end than on the other, engage the finger 4| to cause the container 2| to be advanced in a direction opposite to the direction of motion of the sheet3. It is seen that, by being thus advanced, the container 2| is caused to pass out of the influence of the sheet when only one-half of the length of the sheet has passed from the transmitting conveyor to the folding conveyor 5. When the container passes out of tlfe influence of the sheet, the direction of motion of the folding conveyor 5 is reversed, and one-half of the length of the sheet 3,

'that remains on the transmitting conveyor I, is,

deposited on the remaining half, that has been advanced to the folding conveyor 5. The sheet 3 is thus folded to present a surface of. one-half the length of its original surface.

In Fig. 3, the electrical circuit for the motor l5, which drives the folding conveyor belt 5, is illustrated. The system is shown for the condition assumed for the unexcited state of the photo-tube When the photo-tube I9 is excited, the current thereof. passes through the. exciting coil of a relay 51, and the movable contact 55 thereof opens a circuit from one terminal 6| of a pluralphase power supply, through conductors 63, 85

and 81, the contactor 59 of the relay 51, the exciting coil 39 of a second relay 1| and conductors 13 and 15, to a second terminal 11 of the power supply. At the same time, the contactor 59 closes a second circuit in parallel with the first circuit through the exciting coil 19 of a second relay 8|.

The contactors 83 and 85 of the first relay 1|,

when it is excited, close circuits wherein the two windings 81 and 89 of the motor l5, are connected,

respectively, to two-phase-terminals 6| and 9| of the supply source. The contactors 93 and 95 of the relay 8|, when it is excited, close circuits wherein the windings 81 and 89 are connected,

respectively, to the phase terminals 9| and BI of 5 the source.

One relay 1| is energized whenthe photo-tube I9 is not excited, while the remaining relay 8| is energized when the photo-tube 9 is excited. The direction of rotation of the motor is, therefore, in 0 one' direction when the tube I9 is not subjected to the influence of light reflected from the sheets and is in the opposite direction when the tube I9 is subjected to the illumination reflected from the sheets. 1.

My invention has been shown herein as applied to a specific system, and a specific electrical circuit has been shown as being utilized with the specific embodiment. It is a well known fact that numerous other circuits for reversing a motor in 20 response to the condition of any well-known sensitive device are available, Systems incorporating any of these reversing devices, of course, are equivalents which are within the scope of my invention. 26

Furthermore, it is well to keep in mind that, while my invention has been specifically shown herein as embodying a photo-tube, as the sensitive element, directly connected to the windings of the controlling relay, the photo-tube may be 30 applied in connection with a grid-glow tube, or other gaseous or vacuum discharge tubes of the same type, which become active in response to the condition of the photo-tube; In practice, the

photo-tube is customarily utilized in the control 3 circuit with a grid-controlled glow tube.

Moreover, it is well to point out that a photoglow tube, that is, a gaseous photo-tube, the

terminals of which are maintained in such condition that a disruptive discharge takes place 46'- therebetween when the tube comes under the influence of radiations, is also usable with my invention;

Finally, a specific mechanical structure, in-

cluding a transmitting-conveyor belt and a 3- folding conveyor belt has been illustrated herein as embodying my invention. It is apparent that my invention may be applied with mechanical apparatus of other types. Essentially, only a transmitting element and a receiving element are 56 necessary. These elements need not necessarily be conveyor belts but may be sheet-handling devices of any well known type. They may, for example, be pneumatically-operated or vacuumoperated contrivances of a type well known in 55 the art,

Although I have shown and described a certain specific embodiment of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim as my invention: 1. Sheet-folding apparatus comprising a conveyor for transmitting a sheet of material, a

second conveyor, said conveyors being so disposed that said sheet of material is transferred from said firstconveyor to said second conveyor, and photo-sensitive means for reversing the direction of motion of said second conveyor after a predetermined length of said sheet has been transmitted from said first conveyor to said second conveyor.

2. Sheet-folding apparatus comprising acon-nveyor for advancing unfolded sheets, a second 75.}.

conveyor for advancing folded sheets, photosensitive means, responsive to the presence of an unfolded sheet adjacent to said second conveyor, for reversing the direction of motion thereof, said means being effective to reverse the direction of motion to its original condition after a predetermined length of said sheet has passed to said second conveyor.

- veyor for advancing unfolded sheets, a second conveyor for advancing folded sheets, means, responsive to the presence of an unfolded sheet adjacent to said second conveyor, for reversing the direction of motion thereof, means for moving said reversing means in a direction opposite to the direction of motion of said unfolded sheets when it is under the influence of said sheets and for moving said reversing means in the direction of said unfolded sheets when it is not under the influence thereof.

5. Sheet-folding apparatus comprising a conveyor for advancing unfolded sheets, a second conveyor for advancing-folded sheets, means, responsive to the presence of an unfolded sheet adjacent to said second conveyor, for reversing the direction of motion thereof, means for moving said reversing means in a direction opposite to the direction of motion of said unfolded sheets when it is under the influence of said sheets and for moving said reversing means in the direction of said unfolded sheets a predetermined distance when it is not under the influence thereof.

6. Sheet-folding apparatus comprising a conveyor for-advancing unfolded sheets, a second conveyor for advancing folded sheets, means, responsive to the presence of an unfolded sheet adjacent to said second conveyor, for reversing the direction of motion thereof, and means for moving said reversing means in the direction of motion of said second conveyor.

' conveyor, means, responsive to the presence of an unfolded sheet adjacent to said second conveyor, for reversing the direction of motion 5 thereof, means for moving said reversing means for the total distance covered by said second conveyor in its reverse motion and for moving said reversing means a portion of the distance covered by said second conveyor in its direct motion. 1

8. Sheet-folding apparatus comprising a conveyor for advancing sheets to be folded, means adjacent to said conveyor to receive the unfolded sheets therefrom, and to cooperate with said conveyor to fold said sheets and light-sensitive 15 means associated with said means to regulate the motion thereof,

9. Sheet-folding apparatus comprising a conveyor for advancing sheets to be folded, means to be advanced in a single plane adjacent to said conveyor to receive the unfolded sheets therefrom, and by cooperating therewith to fold said sheets and means for regulating the direction of motion of said means cooperating with said conveyor in such manner that sheets of different lengths are folded proportionally as regards the distance of the ends of the sheets from the folds.

10. Folding apparatus comprising a conveyor for advancing sheets to be folded, means adjacent to said conveyor to receive the unfolded 80 sheets therefrom and by cooperating with said conveyor to fold said sheets and light-sensitive means, to respond to the unfolded length of said sheets, for controlling the operation of said means cooperating with said conveyor. 86

11. Folding apparatus comprising a conveyor for advancing sheets to be folded, means adjacent to said conveyor to receive the unfolded sheets therefrom, means for moving said receiving means alternately in the direction of motion of said conveyor and in the opposite direction thereby to fold said sheets, means, to respond to the presence of an unfolded sheet on said conveyor, for controlling the operation of said moving means and means for moving said controlling means in the direction of said receiving means when said receiving means is moving in a direction opposite to the direction of motion of said conveyor.

ROBERT S. ELBER'I'Y. JR- 

